1. Field of the Invention
The present invention relates in general to optical connectors and, in particular, to a hybrid fiber expanded beam connector that can be used to connect dissimilar fibers such as single mode fibers that have different mode field diameters (MFDs) or different effective areas. The present invention can also be used to connect fibers that are difficult to fusion splice because they are made of glasses with different coefficient of thermal expansions (CTE).
2. Description of Related Art
Manufacturers of optical connectors have been trying to design an optical connector that can be used to connect different types of fibers. This type of optical connector would be desirable because there is an increasing number of different fiber types becoming commercially available including, for example, specialty fibers and dispersion compensating fibers. The specialty fibers and dispersion compensating fibers all have different MFDs and thus different effective areas. Unfortunately, today there are no optical connectors that can connect different types of fibers. Instead, today one has to fusion splice different fiber types to each other which is time consuming and sometimes not very effective (high losses). Accordingly, there is a need for an optical connector that can effectively connect and mode match different types of fibers. This need and other needs are addressed by the hybrid fiber expanded beam connector and methods of the present invention.
The present invention includes a hybrid fiber expanded beam connector that can be used to connect dissimilar fibers such as single mode fibers that have different mode field diameters (MFDs) or different effective areas. It can also be used to connect fibers that are made of glasses that have different composition, and thus different CTE. Optical fibers of different composition and CTE are difficult to bond together reliably by fusion splicing because of high stress at the splice. The hybrid fiber expanded beam connector includes a first lensed optical fiber that is optically coupled to a second lensed optical fiber but physically separated from the second lensed optical fiber. The first lensed optical fiber including one type of fiber is capable of expanding a light beam traveling therein and outputting a collimated light beam. The second lensed optical fiber including another type of fiber is capable of receiving the collimated light beam and focusing the received light beam such that the light beam travels from the first lensed optical fiber to the second lensed optical fiber. In a similar manner, the hybrid fiber expanded beam connector can transmit a light beam from the second lensed optical fiber to the first lensed optical fiber. The present invention also includes methods for making and using the hybrid fiber expanded beam connector.